For the second one you realised that when arranging R you have 4 places to put it and that after you arrange R you have 3 remaining places for N. There remain 2 more letters to form the four letter 'word' from the 4 remaining. Hence, the number of ways you can make the word from the letters of the word 'REASON' if it must contain R and N is 4*3*4*3.

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